This application relates to the art of covers and, more particularly, to covers which are formed in two pieces and releasably held in openings. The invention is particularly applicable to covers for electrical outlet boxes or the like and will be described with particular reference thereto. However, it will be appreciated that the invention has broader aspects and the cover may be used for closing openings in support members other than electrical outlet boxes.
Electrical outlet boxes of the general type shown in U.S. Pat. No. 3,701,837 issued Oct. 31, 1972, to Fork are commonly installed in spaced-apart locations in a floor, and have electrical wires installed therein. Use of any particular outlet box depends upon the location of equipment within the building.
Prior art relating to covers which can be opened or removed for providing access to outlet boxes or the like include U.S. Pat. No. 650,432 issued May 29, 1900, to Stewart who has hinged covers so there would always be an opening through the cover even if the box was not being used. Drilling holes and inserting pins for the hinged connections is relatively expensive.
U.S. Pat. No. 900,382 issued Oct. 6, 1908, to Joynes is simply of interest for a split cover-like member.
U.S. Pat. No. 1,847,377 issued May 10, 1932, to Hubbell is of interest for an outlet box cover which is releasably held in position by spring tabs.
U.S. Pat. No. 2,800,242 issued July 23, 1957, to Sauthoff is of interest for a split cover having openings for pipes or cables. The Sauthoff cover is held in position by bolts.
U.S. Pat. No. 3,015,408 issued Jan. 2, 1962, to Campbell et al is of interest for a plastic outlet box cover which is held in position by integral tabs on the undersurface of the cover.
U.S. Pat. No. 3,335,900 issued Aug. 15, 1967, to Mackiewicz is of interest for a switch box cover having integral fingers for snapping into slots for holding the cover in position.
The following U.S. Pat. Nos. are of interest for split plastic covers: 3,729,572 issued Apr. 24, 1973 to Helin; 3,859,454 issued Jan. 7, 1975, to Mann; and 3,864,512 issued Feb. 4, 1975, to Meadow.
It is also known to have a split cover generally similar to that of Sauthoff with integral tabs on the undersurfaces of the split cover parts like those shown at 24 in FIG. 6 of Campbell. Tabs of this type which are located on the undersurface of the cover and spaced inwardly from the cover outer peripheral edge are quite difficult to release for removing the cover from the outlet box.